Typical musical instruments are designed to be played by a musician through direct physical contact of the musician with some part of the instrument. Attempts to create instruments that do not require direct contact of the musician have generally been approached from either a) mechanical actuators, or robotics, replacing the hands and/or feet of a musician and attempting to replicate the motions of the musician or b) electronic instruments which may be played by control signals from either a computing device or a control surface, such as a keyboard, played by a musician. In the first case, the musical instruments are commonly acoustic instruments and the robotics, which are activated by control signals or mechanical controls, act as the musician, producing sound from the instrument in the same manner as if a human musician were playing the instrument. In the second case, the sound is created electronically and must be converted to an audible sound using an amplifier and loudspeaker.
Some musical instruments are available in two forms: acoustic instruments and electric instruments. Acoustic instruments can be played and heard by an audience without the need for amplification or loudspeaker. An example would be an acoustic piano, which can be heard in a room without any form of electronic amplification. Electric instruments generally require some form of electronic amplification and loudspeaker to be heard by an audience and have an output jack which sends an electrical signal to amplifiers, processing electronics or recording devices. An example would be an electric piano or synthesizer which would require an electronic amplifier and loudspeaker to be heard. Musicians choose acoustic or electric instruments based on the desired sound and application and often will switch back and forth between them based on the song being performed to employ the different sounds.
An acoustic instrument creates an audible sound by the creation of vibrations within the instrument which are generated by the actions of the musician. The vibrations excited within the instrument by the musician are affected by the physical form of the instrument, which serves to excite corresponding vibrations in the air surrounding the instrument. The vibrations of the air around the instrument are carried as sound waves through the air to the ear of the listener. An acoustic instrument generally has a different sound characteristic than its electric counterpart, mainly due to the construction of the body of the instrument, which has a significant impact on the overall sound. Body characteristics, materials, and construction methods that make for a good acoustic instrument are generally quite different than those that make for a good electric instrument.
An electric instrument generates an analog electrical signal in response to the actions of a musician. This signal is sent to an electronic amplifier, which drives a loudspeaker to create sound waves which can travel through the air to the ear of the listener.
Many instruments are available in either acoustic or electric form and some are available in a combined form. One such combined form is the inclusion of an electric sensor or microphone in an acoustic instrument, such as an acoustic guitar, so the instrument may be used as an acoustic instrument or the electrical output may be plugged into other electronics, such as an electronic amplifier. Attempts to provide an acoustic sound from an electric instrument have been attempted by inclusion of a mechanical sensor in an electric instrument to pick up the mechanical vibrations in the instrument and convert them to an electrical output signal. The acoustic properties of the electric instrument are vastly different from those of the acoustic instrument, so these combined form instruments frequently result in a reduction in the sound quality of the electric sound, the acoustic sound, or both.
One problem encountered by musicians is the inability to easily switch back and forth between the acoustic instrument sound and the electric instrument sound in the same performance. In the case of an instrument that is held in the hands as it is played such as guitar, violin, saxophone, etc., the musician must put down or let go of one instrument, for example an acoustic guitar, before playing another, for example an electric guitar. This can interfere with a performance because the musician must stop playing for a period of time while changing instruments. The combined form of an electric and acoustic instrument mentioned earlier is an attempt to improve this situation, but as mentioned previously the body of the instrument greatly affects the sound and the combined form usually results in inferior sound from either the acoustic instrument sound or the electric instrument sound from these combined instruments.
Another problem faced by musicians is that generally only one instrument may be played at a time. If a musician had the capability of having one performance generate sound from multiple instruments, the overall sound could be much fuller and richer. Electronic synthesizers often have the capability of generating multiple sounds from a single performance, but other traditional instruments do not.
Another problem encountered with the existing state of musical instruments is that there is no way to exactly repeat a performance using a different instrument. If a musician plays and records a piece of music perfectly on an electric guitar, for example, and then later decides it would sound better on an acoustic guitar, the entire performance must be repeated and recorded using the acoustic guitar, which can take significant time due to the chance for mistakes.
Yet another shortcoming of the existing art in musical instruments is that all instruments must be available to the musician at the time of the performance. There is a standard called Musical Instrument Digital Interchange (MIDI) which provides for the recording of certain performance information which can then be used to trigger sounds from a synthesizer at a later time, but the standard does not include provisions, method or any mechanism for generating sounds from a real instrument.
What is needed is a way to enable the playing of a musical instrument without the musician having to physically touch it so the musician may “play” multiple instruments at the same, switch back and forth between different instruments without having to stop playing, use a previously recorded signal to play a musical instrument, or play an instrument in a remote location.